This invention relates to the field of devices for adjusting the elevation of manhole covers, catch basin frames or other appurtenances relative to a roadway or greenway surface or the like, and in particular to the use of set screws for adjusting the angular relation of manhole cover risers or other appurtenances in relation to a concrete substrate such as spacers mounted atop a conventional manhole.
Many municipalities may now enforce quite close tolerances in road construction that require the installed manhole cover once mounted onto the manhole cover riser, to be substantially flush with the roadway surface, that is, the surface of the asphalt. For example, in applicant""s experience, at least one municipality requires that the manhole cover be parallel to the asphalt surface and offset from the asphalt surface no more than seven millimetres.
Because the manhole apertures themselves are horizontal, and often the road grade is not horizontal, for example having a grade of up to four percent, or in extreme cases a twelve percent grade and/or a seven percent crossfall, it is conventional that, firstly, a ring or annular spacer, sometimes referred to as a xe2x80x9cdonutxe2x80x9d, is installed onto the manhole aperture, and then a manhole cover riser is mounted on top of the ring spacer. Because the manhole cover risers are very heavy, being constructed of solid metal such as grey or ductile iron, it is often a two-man lift to set the riser onto the ring spacer and then a two-man job to adjust the tilt or incline of the riser on top of the spacer. Typically what is done is one man lifts one side or edge of the riser while the second man inserts makeshift shims, including whatever small pieces of wood or rocks may be to hand, so as to adjust the angular relation of the riser onto the horizontal upper surface of the spacer. In this fashion, the riser is adjusted both vertically and tilted relative to the spacer so as to bring the upper surface of the riser into which the manhole cover fits within the specified tolerances of the anticipated upper surface of the asphalt.
Once a riser has been so adjusted, the roadway construction continues around the riser, for example, as the crush is compacted. This may result in the riser being disturbed before the riser and spacer are encased in concrete so as to leave the riser out of adjustment because of disruption to the shims. This then means that the riser must again be adjusted either before or after the asphalt is laid. Thus, as may be seen, the prior art method of adjusting the manhole cover risers is both labour intensive and prone to later misalignment requiring the adjustment work to be redone.
Therefore there exists a need in the prior art for a simple to install, easily adjustable mechanism for adjusting the vertical height of a manhole cover riser above the concrete ring spacer and for adjusting the angular inclination of the riser relative to the ring spacer.
The present invention is an apparatus for adjusting the height above, and angular relation of a roadway or greenway appurtenance such as a manhole cover riser relative to a substrate such as an annular concrete spacer for mounting atop a manhole aperture. In the case of a riser, the present invention may include a frusto-conical hollow center riser portion having an annular rim rigidly mounted around or atop thereof for receiving a manhole cover concentrically mounted into the upper surface of the rim, and having concentrically base-mounted therearound a base flange, which may be circular or square or any other shape in planform, of a diameter corresponding to the diameter of the annular spacer. At least two and preferably at least three or four get screws or other threaded members included without intending to be limiting cone-point set screws are threadably mounted through the annular flange. Each threaded set screw is threadably mounted to a corresponding threaded bore vertically bored through the base flange. The threaded bores may be equally radially spaced around the base flange about the vertical axis of symmetry of the riser and the coaxial axis of symmetry of the spacer when assembled with the riser.
Each of the set screws may be independently adjusted by being rotated in their threaded engagement in the threaded bores, for example by the use of a tool having a male coupling end releasably engaged into a corresponding female receptacle in the upper ends of the set screws. Rotation of the screws adjusts the distance the set screws protrude from the bottom of the base flange. The lowermost ends of the set screws engage the upper surface of the annular spacer so as to frictionally engage and mate the riser onto the spacer. The engagement of the set screws thereby inhibits lateral movement of the riser relative to the spacer. Each of the set screws may be adjusted in relation to the base flange so that the upper surface of the riser is brought into parallel, substantially flush, relation with the upper surface of the roadway being built. Female mating means may be provided, for example on the spacer, for mating and anchoring of other ends of the set screws. For example an annular groove or channel or segment thereof or other female receivers such as sleeves, collars, cups etc. may be provided on the upper surface of the spacer or a mating seating ring sandwiched between the spacer and the riser.
Advantageously, the tool for adjusting the set screws is a common tool, for example a wrench or key-type tool such as a T-handle allen-key.
In summary the apparatus according to the present invention for adjusting the height and inclination of roadway and greenway appurtenances includes a rigid annular spacer ring sized so as to be mountable onto a manhole, and a manhole riser mountable onto the spacer ring. The riser substantially frusto-conically shaped. A rigid annular base flange may be mounted around a base end of the riser. A plurality of threaded bores are formed in spaced array around the base flange. Rigid elongate threaded members are threadably mountable into the threaded bores so as to be selectively threadably adjustable in the threaded bores and so as to protrude downwardly from the base flange into engagement, beneath the riser, with a top surface of the spacer ring when the riser is mounted on the spacer ring. The threaded members are threadably adjustable in the threaded bores to elevate or to tilt the riser relative to the spacer ring. An annular retaining ring may be provided which is mountable in mating engagement, so as to be sandwiched between, the riser and the spacer ring. The base flange substantially overlaps the top surface of the spacer ring, or retainer ring if employed, when mounted thereon. The plurality of threaded bores may be at least three threaded bores in substantially equally radially spaced array around the base flange. The retaining ring may include at least one retaining flange mounted so as to extend outwardly of the retaining ring for engaging the top surface of the spacer ring when the retaining ring is mounted thereon and for alignment under the threaded bores when the riser is mounted on the retaining ring. The retaining ring may have a lower rim for mating inside the spacer ring and an upper rim sized to engage an inner surface of the riser so as to space and center the riser above and over the retaining flange before the threaded members are engaged with the retaining flange. The upper rim may be flared outwardly.
Female retaining means may be mounted on the at least one retaining flange for mating with lowermost ends of the threaded members. The female retaining means may be at least one corresponding length of channel in a top surface of the at least one retaining flange. The length of channel may be an annular groove and the at least one retaining flange may be an annular flange extending around the retaining ring.
Preferably, the lowermost ends of the threaded members are not concave. For example, advantageously the lowermost ends of the threaded members are bullet-shaped and the female retaining means mate substantially conformably, that is, so as to conform with, the shape of the lowermost ends. In one embodiment the threaded members are set screws. Protective caps or other protective means may be provided for snug mounting or application onto the uppermost ends of the threaded members.
The method of the present invention for adjusting the height and inclination of roadway and greenway appurtenances includes the steps of:
a) mounting onto a manhole opening a rigid annular spacer ring sized so as to be mountable onto the manhole,
b) mounting a manhole riser onto the spacer ring, wherein the riser is substantially frusto-conically shaped and has a rigid annular base flange mounted around a base end of the riser, a plurality of threaded bores formed in spaced array around the base flange,
c) threading rigid elongate threaded members into the threaded bores and selectively threadably adjusting the threaded members in the threaded bores so as to protrude downwardly from the base flange and engage a top surface of the spacer ring,
d) adjusting the threaded members in the threaded bores to elevate or to tilt the riser relative to the spacer ring.
The method may also include mounting an annular retaining ring in mating engagement sandwiched between the riser and the spacer ring.